I was working on Exchange 2007 SP1 to upgrade it to SP3. I upgraded the server with SP3 without any issue and restarted the server. After the restart i found that MS Exchange Information Store service is not started. I tried to start it manually but it failed with event id 5000.
As per the support article http://support.microsoft.com/kb/944752 but in my case it wasn't the issue.I was getting the error message:
Unable to initialize the Microsoft Exchange Information Store service. Failed to find the working directory parameter from the registry - Error 0x80004005.After doing little bit of research i found that i have to make changes in the registry.I went to the registry Editor on the server:Under this Registry Key:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystemAdd a new String Value and call it "Working Directory"Enter the path for the working directory C:\Program Files\Microsoft\Exchange Server\Mailbox\MDBTempNote:You need to make sure that you have the right name of the String Value and the location i.e C:\Program Files\Microsoft\Exchange Server\Mailbox\MDBTempAfter making the change, restarted the Exchange Server and MS Exchange Information Store Services started successfully.Cheers,-Gulab